Backtracking regexes matchers are a Bad Idea. It's true you need them to implement backreferences. But I've never used such a thing. If I were creating a run

Backtracking regexes matchers are a Bad Idea. It's true you need them to implement backreferences. But I've never used such a thing. If I were creating a runtime for some new language, I would simply ignore that part of the POSIX standard.